A Few Folding Electric Bikes

I’ve been looking into folding electric bicycles – as if I can afford one – so I can climb the three hills on my ten mile commute to work without getting too sweaty. There are dedicated folding electric bikes – which I’ll discuss later – but most are just folding bikes retrofitted with kits by Bionx or Currie.

The neatest retrofit I had seen until today was NyceWheels’ Tern Link + Bionx RR (rear rack) install. With the battery tucked in a rack, it is well-disguised for the streets of NYC, where blatantly electric bikes are technorata-non-grata. Unfortunately the $2,150 Tern Link is only for riders who weigh less than 110 kg/242 lbs – and I fluctuate ten lbs above and below that number depending on the season. The 110 kg weight limit cuts out all the Dahons and most of the Terns and Bromptons for me.

The 26″ wheel Tern Joes and the 24″ wheel Tern Eclipses will carry 115 kg, and fold as well as the Link. I emailed NyceW about doing an RR install on the $900 P24, but Steve claims that it would be difficult because of the disc brakes. (I have seen it done in another NyceW video.) The DT – downtube – installs look clumsy, and I suspect that swinging my leg over the top tube-mounted battery would be a pain at stoplights. The Joe weighs in at 30.7 lbs and Bionx kits range from 14 to 20 lbs, so a retrofitted Joe should weigh 45 to 51 lbs.

Two of the Tern Eclipses come with rear racks, but the S11i already costs $2,500 and the S18 already costs $2,100 without any electrics. These Eclipses are already 32.4 and 34.8 lbs so electric assist would increase weight to between 47 and 55 lbs. The $1,100 P9 looks like a good candidate for electric assist, but with no rear rack and disc brakes, I’m guessing Steve would say I’d need a DT install. A P9 with the DTs should weigh between 41 and 47 lbs.

NyceW’s front wheel drive retrofit of a Brompton should attract even less police attention. The M3L would carry me, but putting both the weight of the electric hub motor and the battery bag forward of the rider should radically change the weight distribution of the tiny bike. Also, the M3L plus the battery bag will cost $3,000 dollars or more.

Almost ten years ago, I test rode a Montague Paratrooper trail bike configured as the Wavecrest Tidalforce e-bike, with a hub motor in one wheel and a hub battery in the other. Wavecrest is long since defunct, but NyceW offers two sturdy Montague packages, the $1,950 to $2,850 Crosstown + Bionx and the $2,100 to $3,000 Paratrooper + Bionx. In these 43 lb packages the battery is mounted DT style on a locking tube just above and ahead of the pedal axle. It isn’t as elegant as the hub battery, but it looks less clumsy than mounting above the top tube. Either of these will carry 250 lb riders, and rather quickly.

In the realm of dedicated folding electric bikes, Prodeco makes less expensive but heavier machines with lithium iron phosphate batteries. The $1,400 Mariner, Storm and Genesis have 8 speeds and weigh in at 46, 49 and 55 lbs, respectively. The $1,300 step-through Stride weighs 46 lbs. Prodecos are cheaper at Amazon, where Zap has a good video review of his Storm. Reviews are generally positive, but many note that the range is lower than promised, and even Zap admits that you don’t want to pedal a dead Storm uphill. Seems like a good bike for retirees.

Looking at the weights of these other bikes, I appreciated that my folding Xootr Swift is very light at about 11.2 kg/25 lbs. Some of the Bike Friday models are a pound lighter, but at twice the price. I dropped an email to Xootr asking if they had experience adding a Bionx system using the CrossRack, which mounts behind the saddle.

They did not, but they told me that Xootr will soon be selling the 16.5 kg/36 lb Swift-e – an electric assist version of the Swift – in the US. The 36V 9Ah Swift-e is reviewed in this PDF from a UK bike magazine, and should list for under $2,000. From the pictures, one would hardly notice that it is an electric bike. I only live three hours from Scranton, so I wonder if they would retrofit my Swift if I drove it up there.